Colorado Public Works Journal, Winter 2024

46┃ Colorado Public Works Journal Angela Folkestad is the Executive Director of ACPA, Colorado/Wyoming Chapter and can be reached at afolkestad@pavement.com ACPA COLORADO/WYOMING CHAPTER Angela Folkestad Optimizing Concrete Pavement Opening to Traffic New approaches to roadbuilding can take decades to be accepted – opening strength requirements for concrete pavement fall into this category. Why not take the opportunity to open pavements earlier with a lower strength while still providing great performance? Engineers and owners tend to be most comfortable with properties they can measure, and this has led to concrete strength being a high priority. It has also led to the perception that higher strength means better concrete. Over the last decade, it has become increasingly obvious that strength is not an indicator of durability. Increasing the strength of concrete does not lead to a corresponding increase in durability, especially with concrete pavement. Factors of safety are important in many aspects of engineering, but they can become excessive, and this seems to be the case when it comes to opening strength requirements for concrete pavement construction and repairs. The concept of 28-day design strength does not mean that a concrete pavement cannot be opened to traffic until 28 days after paving. It also doesn’t mean that design strength must be achieved before the pavement can be loaded with traffic, but knowing the in-place strength before opening is important. Maturity testing is a great tool to implement optimized opening to traffic. It correlates in-place concrete strength with lab testing by utilizing measurements of strength and temperature measured in the lab and tracking field properties with sensors embedded in the pavement. The Standard Method of Test for Estimating the Early Opening Strength of Concrete Pavements by Maturity Tests was just approved by AASHTO to make this process even simpler for use in concrete pavement. Researchers at the University of Pittsburg have published a free online tool that uses early opening damage analysis to determine cracking risks for a given pavement system loaded at a given strength: https://software.pavements.pitt.edu/EOP-National. The National Concrete Pavement Technology Center (CP Tech Center) has also compiled a technical summary of information on optimizing opening to traffic that can be accessed with the QR code provided. From a sustainability perspective, optimizing concrete pavement opening to traffic reduces overdesign and can result in reduced cement contents in the mix. Learn more about optimizing concrete pavement opening to traffic and maximizing your asset management dollars at the Annual Concrete Pavement Workshop on Thursday, February 29th (Leap Day!) in Denver. Registration is open on our website at www. cowyacpa.org.

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